Rotary dental brush



June 2 1959 E. o. COGGESHALI.V 2,888,697

ROTARY DENTAL BRUSH Filed Aug. 29, 1955 IN VENTOR MMM 0 @WMM/2 BY Mn/4% M M v ATTORNEY grooves in the surface 4of the workpiece. ydisadvantage is that the commonly used brush ftends to United States Patent ROTARY DENTALIBRUSH Edward Owen Coggeshall, Shirley, Mass.

Application August 29, 1-955, Serial No. 530,958

2 Claims. (Cl. 15-179) This invention relates to a brush arrangement for polishing dental appliances, such as bridge work and the like, and, more particularly, it is directed to 'a 'rotary brush in which rotary and reciprocatory components 'of vmotion are imparted to the bristles at the point of Contact with the surface beingipolished.

The brushes used by the dental technician in polishing normally consist of a disc-like hub havin'g'a cylindrical hole formed at the axis thereof and `havin-g an annular row of bristles around the periphery of the disc. Polishing is eiected by'rotating the brush aboutits axis at high speed and engaging the bristles with `the surface 'to `be polished. Two principal disadvantages attend'thepolishling operation with .such known brushes. The'r'st'is .that

the annular ring Yof bristles tends to .form yundesirable The second throw a large portion-of the pumice used in the operation.

The present invention is designed to overcome the disadvantages of-the -prior art. The essence of -t'heinvention is to provide means for imparting a reiprocatory component of motion to the normal rotary motion at the point of contact with the workpiece. The added component of motion has a tendency to minimize the throwing of pumice and substantially avoids the problem of cutting grooves into the polished surface.

Several forms will be described in detail below. Each has a prinicpal advantage over the others, and all have the common denominator of combining the two components of polishing motion. In the preferred embodiment, the annular ring of bristles lies in a plane inclined to the plane normal to the axis of hub rotation. Rotation of the hub about its axis therefore necessarily imparts a reciprocatory component of motion to the bristles at the point of Contact with the workpiece.

In the second and third forms, a standard brush is used, and each is provided with a ball and socket connection between the brush and the driving mechanism, so that the brush may be set at an angle to the axis of rotation. In the first of these two embodiments, the socket is formed in the hub of the brush and the driven chuck has a ball engageable with that socket. In the second of the last two embodiments, a standard hub is used with the standard arbor chuck, except for the fact that the end of the arbor chuck is formed with a ball which engages the socket member.

The last form has the advantage that the standard chuck can be used, thus permitting a rapid interchange between the brush, on the one hand, and the other tools normally used by the dental technician.

It is a principal object of the invention to provide a dental polishing brush having means for imparting a combined reciprocatory and rotating component of motion to the bristles of the brush at the point of contact with the workpiece.

Other objects of the invention will become more readily apparent from a consideration of the following "icc `detailed description of the invention taken in-conjunction with the accompanying drawings, in which:

Fig. 1 is a plan view of therotary brush constructed according to the invention;

Fig. 2 is an exploded view in elevation, showing the brush and the arbor chuck;

Fig. 3 is a plan view of an alternative embodiment;

Fig. 4 is an exploded view of the alternative embodiment;

Fig. 5 is a sectional view through the center of the brush in the alternative embodiment;

Fig. 6 is an exploded view of a second alternative embodiment; and

Fig. 7 is an elevational view of the second embodiment in assembled condition.

The preferred embodiment of the invention is shown `in`Figs. l and 2. The rotary brush consists .of a cylin- .drical supporting member or hub 10 which is rotatable .about its axis and into which bristles 12, of equal length and generally perpendicular to the axis of rotation, are set in any suitable, known manner. Formed in the supporting member 10 is an arbor receiving hole'14formed by two frusto-conical surfaces 16.

One of the essential features of this embodiment is shownbest in Fig. 2. In this figure, it will `be observed Vthat Vthe bristles lie in aplane which is 'inclined at ian .angle to the plane normal to the axis of the Asupporting member. Thus when the brush is rotated atjhigh speed around its axis, with the bristles engaging a surface to be polished, the bristles have a reciprocating component of motion at the point of contact with the workpiece. This reciprocating component of motion tends to avoid 'grooving of the surface 'being polished and minimizes the'spraying of the pumice during thepolishing operationA Further, 'a larger surface larea `is covered, -thus speeding the polishing operation.

Fig. 2. also demonstrates another aspect of the invention, namely, the manner in which the brush cooperates with an arbor chuck l. The arbor chuck I8 has a tapered screw-threaded portion 20 which is standard for engagement with most of the tools of the dental technician. The frusta-conical surfaces 16 of the 'bristlesupporting member 10 have a taper designed for receiving a standard tapered arbor chuck, as shown, in screwthreaded engagement. This arrangement permits a large number of threads in the chuck and hole to 'be mutually engaged, thus holding the brush hub steady during the polishing operation.

A second embodiment is shown in Figs. 3, 4 and 5. In this embodiment, bristles 22 are mounted on a sup porting member or hub 24 in the standard manner with the plane of the bristles lying in a plane normal to the axis of the supporting member. The supporting member, however, is formed with a generally semi-spherical recess 26, which cooperates with a specially designed chuck 28.

The chuck 28 has a shank 30 which cooperates in the usual manner with mea-ns for rotating the chuck. The hub-receiving end of the chuck is formed with an oblate spheroid member 32 formed of rubber or other similar material having the characteristics of resilience and a high friction surface. The member 32 is xed to the shank 30 by a bolt 34 and washer 36, the bolt 34 being threaded into the suitable recess 38 formed in the shank of the chuck. The shank has an annular ange 40 which engages the side of the spheroid member 32 remote from the washer 36.

The size of the member 32 is such that it will iit snugly in the semi-spherical recess 26 of supporting member 24, and can be firmly retained in that recess by tightening down bolt 34, which tends to compress the spheroid member 32, expanding its peripheral surface against the surface of recess 26.

The manner in which the device is used is best shown in Fig. 5. That figure demonstrates that the plane of the bristles can be inclined to any suitable angle by properly positioning the supporting member 24 with respect to the chuck prior to the tightening of bolt 34.

The device of Figs. 3 to 5 has the disadvantage of lack of convenience in the technicians normal operation. In such operation, the technician finds it convenient to use a standard arbor chuck to which so many of his operating tools are attacbable. "fue embodiment of Figs. 6 and 7 show how the advantages of the brush having the reciprocatory component of motion can be combined with the standard arbor chuck without necessitating the use of a specially designed brush.

in this embodiment, the arbor chuck having the standard tapered portion 44 is provided at one end thereof with a ball-shaped shank 46. Cooperating with the shank 46 is a bifurcated socket member 48 Which is threaded along a major portion of its length at 50. A

nut 52 cooperates with a thread 50 so that when the nut 52 is turned down toward the socket portion 43, the tWo portions of the socket member clamp down on the ball 46.

The remaining part of the socket shank is shown as it appears before being xed to a member 54, by which the device is attached to the driving arrangement. vantageously, after the nut 52 is threaded onto the portion 50, the portion 50 can be Welded to the member 54.

It Will be apparent that the arbor chuck may be set at any angle, Within a Wide range, to the axis of rotation of the driven member 54. Thus reciprocatory components of varying amounts of motion can be applied to a standard brush attached to the end of the chuck. The undesirable vibration accompanying the use of this embodiment of the invention is compensated for by the adaptability of the arbor to a large number of the other tools normally used by the dental technician.

In a general manner, While there has been disclosed in the above description what s deemed to be the most practical and ecicnt embodiment of the invention, it

il should be well understood that the invention is not limited to such embodiment, as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention, as comprehended Within the scope of the accompanying claims.

l claim:

1. A rotary brush comprising a cylindrical hub rotatable about its axis, a row of bristles mounted in said hub around the cylindrical surface thereof, said bristles being of substantially equal length and individually extending generally perpendicular to said axis all around the periphery of said hub, said row of bristles having adjacent increments thereof offset With respect to each other along said axis to provide a generally circular endless periphery lying in a plane inclined to said axis, the projection of said brush in the direction of said axis being circular.

2. A rotary brush comprising a cylindrical hub rotatable about its axis, a row of bristles mounted in said hub around the cylindrical surface thereof, said bristles being of substantially equal length and individually extending generally perpendicular to said axis all around the periphery of said hub, said row of bristles providing a generally circular endless periphery lying in a plane inclined to said axis, the projection of said brush in the direction of said axis being circular References Cited in the file of this patent UNITED STATES PATENTS 1,076,022 Conner Oct. 21, 1913 1,283,599 Thomas Nov. 5, 1918 1,467,874 MuchOW Sept. 11, 1923 1,795,098 Scadding Mar. 3, 1931 1,969,549 Eppstein Aug. 7, 1934 2,324,272 Anderson July 13, 1943 FOREIGN PATENTS 12,802 Great Britain 1889 555,643 Germany July 7, 1932 i itil 

